1. Field of the Invention
1. This invention relates to network communication systems. More particularly, it relates to modification of frames (message packets) in nodes forming a path from sender to receiver.
2. Description of the Related Art
Packet switching networks operate by relaying data along a series of nodes from a sending node to a final receiving node. These nodes or points are often computers programmed to process the frames, forwarding them to other nodes if necessary according to routing information in the frame.
Communications among computers and networks operate at ever-increasing speeds. There are also a number of differing protocols, often requiring changes to formats along the communication paths. Protocols dictate the format of header information which includes source and destination addresses and data which can include digitized voice data. The information transmitted in packets or frames is usually of predetermined sizes although there is flexibility in the dimensions of message frames. Frame alterations or modifications sometimes need to be changed, added to, or deleted from frame headers. The changes can be implemented in hardware but hardwired modification circuits are not as versatile as software implementations which can be more easily changed albeit slower in operation. A hybrid system uses a combination of hardware, universal in nature, and software for control.
There are several known systems for processing frames in a network structure. The simplest might be merely to transmit the information to the next terminal. More adaptable systems may use frame alteration at each node for more efficient transmission through the network